White noise and neuronal porosome complex: transmission electron microscopic study

Abstract

In the present electron microscopic study the effect of continuous white noise on the morphology of synapses and neuronal porosome complex (the neurotransmitter-release or secretory machinery) in two subcortical auditory brain regions-colliculus inferior and medial geniculate body in cat, were investigated. Several morphological alterations in some synapses were detected in both subcortical areas. These alterations mainly indicate to the decrease of functional activity of synapses. Rarely important pathological modifications in pre-and post-synaptic regions were detected. In addition to descriptive studies, the morphometric analysis of porosome diameter and depth was performed in colliculus inferior and medial geniculate body. The results revealed that while white noise has no effect on the porosome diameter and depth in colliculus inferior, it provokes significant alterations in the morphology of porosome complex in medial geniculate body. In particular, the significant increase of porosome depth in this nucleus may reflect the alteration in neurotransmission.

The neuronal porosome complex in health and disease

“…Careful examination of the porosome proteome demonstrates the participation of several porosome-associated proteins previously implicated either in neurotransmitter release or in various neurological disorders, 48–98 further confirming the involvement of porosome-associated proteins in crosstalk within the complex and in the regulation of neurotransmitter release. Therefore, certain porosome proteins could be potential drug targets to help ameliorating various neurosecretory disorders.…”

“…In addition to the earlier molecular studies on the involvement of porosome proteins in neurotransmission, recent morphological studies on the neuronal porosome complex have also shed light on both the health and disease states of the neuronal porosome complex as examined using high resolution EM. [88][89][90][91][92] Ultrastructure of the neuronal porosome complex in rats subjected to continuous white noise that is relevant to the increasing, random noise encountered by humans in present day environment, and also known to provoke diverse effects on different regions of the brain, [93][94][95][96][97][98] demonstrates alteration in the porosome length. 92 Constant exposure to such noise is further known to sabotage the development and normal function of the auditory and some other brain regions, and ultimately impair hearing, language acquisition, 93,94 memory performance, 95,96 and other cognitive functions.…”

“…8,9,13 A number of these porosome proteins have previously been implicated in cell secretion. 6,7,111–114 Neuronal porosome-associated proteins previously implicated either in neurotransmitter release or in various neurological disorders 48–98 have been further discussed in this article. Immunoisolated porosomes from neuronal tissue resolved using sodium dodecyl sulfate polyacrylamide gel electrophoresis, followed by SYPRO staining of the resolved protein bands in the gel, demonstrate the presence of 15 bands ranging from >205 kDa to >6.5 kDa in molecular weight, and show the presence of nine additional proteins besides those determined using mass spectrometry (Table 1).…”

“…88–92 Ultrastructure of the neuronal porosome complex in rats subjected to continuous white noise that is relevant to the increasing, random noise encountered by humans in present day environment, and also known to provoke diverse effects on different regions of the brain, 93–98 demonstrates alteration in the porosome length. 92 Constant exposure to such noise is further known to sabotage the development and normal function of the auditory and some other brain regions, and ultimately impair hearing, language acquisition, 93,94 memory performance, 95,96 and other cognitive functions. The chemical basis of such alterations besides elongation of the porosome complex and the rapid synaptic vesicle fusion resulting from such morphological change to the porosome may reflect the corresponding abnormalities in neurotransmitter release that is currently being investigated.…”

Cell Secretion and membrane fusion: highly significant phenomena in the life of a cell

“…This stressogenic environment has an important impact on organisms, by affecting more or less (depending on the stress factor) the functions of different cells in various tissues. The effects of one stress factor, namely white noise, on the organization and function of neuronal porosomes in the cat were investigated in the original paper by Mzia G. Zhvania and her collaborators 10 and discussed in the current Special Issue. Using transmission electron microscopy, the authors studied the effects of continuous white noise on porosome ultrastructural features (diameter and depth) in inferior colliculi and in the medial geniculate body neuronal synapses.…”